Sequoia Aircraft Corporation F.8L Falco, Construction Manual

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F.8L Falco Construction Manual 16–3 Revision 4, March 1, 2002
Figure 1
If you wish, you can make plywood plates for each end of the assembly at hand. A vertical line
can be drawn on the plate and the plate used to support alignment strings for the leading edge,
trailing edge, or any other part of the assembly. With the stabilizer or elevator, you will need a
plate for the center of the aircraft as well. Most builders find this method too fussy and don’t
bother with it.
So far, all builders have built the horizontal tail with the methods described above. A few builders
have built the vertical tail “on the airplane”; that is, they did not use a jig at all but put the
vertical spars in the fuselage jig and fitted in the ribs. While this has worked, we don’t think that
this is really the best way. It is much easier to align the ribs to the vertical plane with plumb bobs
or levels than it is when the tail is on the airplane.
The problem is that the spars of the vertical fin must be glued to the spars of the horizontal
stabilizer. One builder solved this problem by building his vertical tail section first. When the
horizontal tail was assembled, a block of wood was used as a spacer between the two stabilizer spars
to make sure that they were the correct distance apart. The vertical tail was mated to the
horizontal tail on the fuselage jig, and the forward fin spar is flexible enough to spring open for
gluing.
Remember, you should always scuff-sand birch plywood before gluing. When birch plywood is
made, the hot press leaves a hard shiny surface to the plywood, and the glue will adhere better if
this sheen is removed by a light scuff sanding.
In this manual, we will be reminding you to varnish the many pieces. As a practical matter, most
builders find it easier to do most of the varnishing in advance. It is much easier to varnish all of
the nooks and crannies of the ribs if you can hold them in your hand. You should be very careful
to avoid varnishing any area that will be used for gluing.
You will also find that it is necessary to mask the spars and ribs for varnishing. While it may seem
possible to brush varnish only on the areas you intend, the reality is that the varnish inevitably
gets on the surfaces that will later be used to glue on the skins. If you try to wipe up the varnish,
you will find that you will only smear it into the wood.